If they are found to have violated the rules, they could be fined up to 3 million won ($2,700) depending on the number of times they have committed the same offense, according to the Ministry of Environment.

Retailers will instead have to offer the customers paper bags, plastic garbage bags or shopping baskets. The restriction on plastic bag usage is in line with the Environment Ministry’s efforts to conserve resources and promote recycling.

After three months of test enforcement starting on Jan. 1, the rules went live Monday.

Plastic bags can still be used to package food that can leak, like fish, meat or tofu. Items that could melt, such as ice cream, or mud-covered vegetables, are also exempt from the regulation. Through the measure, the Environment Ministry expects to reduce the use of plastic bags by 2.2 billion a year.

Several e-commerce operators, including Coupang, have received complaints from customers for their packaging.

The problem is especially evident for fresh produce deliveries, which are often packaged in material much larger than the item itself.

According to a spokesperson for Coupang, it is difficult to deliver fresh items in good condition without using a significant amount of packaging material, but they added that the company is aware of the issue and plans to tackle it.